This application relates to a thrust bearing shaft incorporated into a compressor for use in supplying cabin air in an aircraft.
Compressors are known and include a motor driven to rotate a shaft and in turn drive a compressor rotor. Typically, there are bearings incorporated into a housing which support the shaft for rotation. One known type of bearing is an air bearing.
In one known air bearing, cooling air is brought into a bearing cooling inlet. The cooling air passes along thrust bearing surfaces, and then may pass between the shaft and various housing portions. The thrust bearing surfaces are spaced from a disk which rotates with a thrust shaft. The thrust shaft rotates with the motor rotor, and the compressor rotor.
The thrust bearing surfaces include a pair of surfaces on axial sides of the disk. Air passes along both of those surfaces. Air on one side of the disk passes along an outer periphery of the thrust shaft, and air on an opposed side of the disk will pass into a bore within the thrust shaft. This air passes through a plurality of holes formed in an internal ledge in the thrust shaft. A portion of this air can then pass radially outwardly through holes in a cylindrical portion of the shaft, while a separate portion continues along the bore of the thrust shaft. In the past, there has been insufficient cross-sectional flow area in the ledge to ensure adequate air flow.